Guided bone regeneration around endosseous implants with anorganic bovine bone mineral. A randomized controlled trial comparing bioabsorbable versus non-resorbable barriers

Background: Guided bone regeneration (GBR) is a viable treatment for osseou s defects surrounding dental implants. Controversy exists regarding the cho ice of barrier membrane used and the method of membrane fixation to achieve GBR. Methods: This study compared the efficacy of a porcine-derived bioabsorbabl e collagen membrane and an expanded polytetrafluoroethylene (ePTFE) membran e (non-resorbable) for GBR using a bovine bone xenograft/autograft bone com posite in defects surrounding dental implants. The study also examined the effect of primary barrier fixation on GBR. Defect size was recorded at Stag e 1 and 2 surgeries (performed 6 months apart). Forty-eight subjects (41% m ales, 59% females) requiring GBR were treated with either collagen (23) or ePTFE (25) barriers, respectively. Implants were titanium self-tapping scre w-type. In 34 GBR sites, barrier fixation was achieved with polylactic acid resorbable pins. The remaining barriers were secured with the implant cove r screw and/or embedded beneath the flaps. Results: At 6 months, a decrease in defect width (collagen barrier 1.95 +/- 0.60 mm, ePTFE barrier 2.65 +/- 0.56 mm), length (collagen barrier 2.65 +/ - 0.61 mm, ePTFE barrier 2.26 +/- 0.66 mm), and circumference (degrees) (co llagen barrier 57.7 +/- 18.7, ePTFE barrier 80.2 +/- 19.9) was observed for both membranes. A significant number (chi (2), P = 0.041) of postoperative complications occurred when barrier fixation was lacking at initial surger y. Furthermore, a significant difference (P <0.05) in the success of GBR wi th respect to defect size was observed when barrier fixation was taken into account. Conclusions: In conclusion, both collagen and ePTFE barriers proved suitabl e for achieving GBR of osseous defects surrounding dental implants. The res ults of this study stress the importance of barrier fixation at the time of initial surgery.